When I saw the heart lock charms I wasnt sure what I was going to do with them when I purchased them. However when I found the keys this project was hatched. Basically just centered heart lock on chain, then attached by jump ring. Same amount of links out on each side attached keys by jumpring. Same step for black puff hearts. This was my first necklace I created and I'm still in love with it.
TIP: Its easier to make necklaces like this by picking a larger, chunkier chain. That way is lays flatter on the neck and you don't have to worry about charms flipping, and it is easier to find jumprings to fit through both the chain and the charm at the same time. :-)